Download CHAPTER 15-17: EVOLUTION: EVIDENCE OF CHANGE

CHAPTER 15-17: EVOLUTION: EVIDENCE OF CHANGE
15-1, 15-3 Evolution: Process of change over time - ** before knowledge of genetics
- The process whereby modern organisms descend from ancient ancestors
- Eg.Tiger descended from Saber-toothed Tiger
Charles Darwin – founding father of Evolution
- Traveled on the ship HMS Beagle to see different life forms
- Island called Galapagos had a diversity of life (a variety of different
organisms)
- It is estimated that there is between 3-20 million different organisms on
the Earth, and several hundred million have come and gone.
Fitness: _______________________. Having favorable traits to survive in your
environment. Traits can be ____________ or ___________ Eg. White fur on a polar bear.
The more fit the species, the more able that species will be to survive and reproduce.
Common Descent: A principle whereby all organisms have __________________
Adaptation: To adapt to better fit your environment. (Now we now: By
mutation!!!!!!!!)
Eg. Long necked giraffes
Evidence in Stone – pg 418-420
Fossils: An organism hardened, or that is preserved in stone over a long period of time.
Fossils are found in sedimentary rock. This is why only a small fraction of past organisms
are found in stone. If a fossil is found on the top layer of the rock it is a more recent
fossil than one lower in the layers. – Law of Superposition fig 17-3
_______________: age of fossils is determined by comparing its placement with
that of fossils in other layers of rock.
__________________: Use of radioactive carbon to date fossils. Scientists use this to
calculate the age of a sample based on the amount of remaining radioactive isotopes it
contains. Helps determine __________________.
Evidence of Evolution in Living Organisms
1. ________________________: embryos of many animals are very similar to
humans.  common ancestor? Fig 15-17
2. ______________________: structures that are similar in origin.
- E.g. Similar bone patterns in whale flipper and human arm and bat wing
- vestigial organs – traces of organs once there. Eg. Appendix in human
and leg bones on a python. Fig 15-15
3. _______________________: All organisms have DNA and RNA and
replicate in a the same way.
4__________________________ – similar animals in different locations were the
product of different lines of evolutionary descent.
5. _________________ – provided evidence that living things have been
evolving for millions of years.
15-2 EVOLUTION THEORIES
Lamarck’s Theory : evolution over time, first to hypothesis that organisms are adapted
to their environment.
1. Tendency towards perfection – all organisms have an innate tendency toward
complexity and perfection. Constantly changing and adapting.
2. Use/Disuse theory: use or disuse a body part and pass on that trait.
Fig 15-7 e.g Short neck giraffe, Body builders
 could stretch their neck and pass on to offspring.
3. Inheritance of acquired traits - passing on acquired characteristics to your
offspring that you got from other sources.
** incorrect – didn’t know how traits are inherited and thought that behaviour had
no effect on organisms inheritable characteristics
Influences on Darwin’s Theory of Evolution pg 374-377 – make a chart
Person/thoughts **more detail on Lyell, Hutton , Lamark and Malthus
Person and year(s)
Contribution
*What determines which individuals survive and reproduce?*
*Darwin’s Theory of Evolution*: Theory of Natural Selection 15-3
Coined the term “The struggle for existence”, which is an organism’s fight against both
the environment and each other for right to live. Use pg 386 – Summarize 5 points
Survival of the fittest:
 only species with traits well suited to their environment will survive and pass on their
traits.
 species without traits well suited to their environment will not survive and not pass
on their traits. e.g short neck giraffes died, long necks lived and passed on their traits.
Natural Selection in action: The Peppered Moth example. KNOW IT!!!! –
photocopied sheet and questions
Genetics and Evolutionary Theory Chp 16-1
-
DNA is the material of heredity. It is what makes up chromosomes, which we get
from our parents.
Chromosomes are broken up into sections called _________ which code for different
traits. (eye colour, widow’s peak, etc.)
-
__________________ are a group of organisms that can interbreed. Every
population has a common group of genes called _______________.
-
Each gene for a trait has a number of different _______________.
Ex.
Gene
Hair colour
Alleles
blonde, red, brown, black
Relative frequency: the number of times that an allele occurs in a gene pool
compared with the number of times other alleles for the same gene colour occur.
See fig 16-2
- example of evolutionary change is the colour of the peppered moth. In
industrial areas of England, the _________________ of the dark colour
allele is increased.
Sources of Genetic variation
1. Mutations – change in DNA
2. Gene shuffling – from sexual reproduction and production of gametes
___________________ – an allele that becomes common by chance
_____________________ (Hardy-Weinberg priniciple) – allele frequencies in a
population will remain constant unless one or more factors cause frequency to change. If
it doesn’t change, the population will not evolve.
List and explain the 5 conditions required to maintain genetic equilibria:
16.3 Speciation: The Development of a New Species
Speciation – the formation of a new species
- Niche: an organisms profession and place where it lives.
For example: two butchers on the same street, side by side, will not
coexist or “occupy the same niche.”
The more efficient species (butcher) will survive and drive the less
efficient species to extinction.
Three types of isolating mechanisms: pg 404-405
The Process of Speciation: The most common way is by reproductive isolation.
Which is the separation of populations, either geographically or by
courtship behavior of differences in appearance. Behavioural,
geographical or temporal isolation.
Explain the 3 types of isolating mechanisms:
Type
Description
Speciation in Darwin’s Finches: KNOW IT!!!! Fig 16-13
Use p.406-409 – Summarize
Founders arrive
Geographical isolation
Changes in the Gene Pool
Reproductive Isolation
Ecological Competition
Continued Evolution
Additional
Information/Unanswered questions
17.4 Adaptive Radiation: One species giving rise to many, also called
__________________ evolution
Example fig 17-22 p.436
_________________ – mature differently in form and in
different organisms, but come from the same origin or embryonic tissues
Lizard
Salamander
Newt
iguana
Gecko
snake
Convergent Evolution: 436-437
CONVERGING TO LOOK THE SAME
Dolphin
Whale
Shark
Porpoise
_____________________: are structures that are similar in form but come from
different origins. Ex. Whale flipper and shark fin
Other sources of evolutionary change.
Gradualism – the theory that evolution is a gradual change
Mass Extinction: When many species vanish
Punctuated equilibria (17-4 p439) – a theory that evolution consists of a pattern of long
period of stability interrupted by brief periods of change.